If anyone expected Israel’s war with Hamas to end with a unilateral ceasefire, the last several days should serve as a rude shock. Ten days after Israel pulled out of the Gaza Strip, Hamas resumed rocket fire and Israel struck back with at least 100 air strikes — including targeted assassinations of Hamas leaders.

That Israel is committing itself in a war of attrition with Gaza after pulling its forces out should come as no surprise. The Israel Defense Forces (IDF) went in without clear objectives, meaning that its attempts to reduce — let alone end — Hamas’s weapons and tunnel systems were bound to come up short. The result is an extended air campaign that may last days, weeks or even months.

The operation committed some of the Israeli army’s heaviest units, including the heavily-armored 36th Division, a veteran unit formerly based in the Golan Heights and which now serves as Israel’s emergency shock force, available to be called into action on short notice. The Israeli invasion also included three infantry brigades, a parachute brigade and territorial infantry units – in addition to large numbers of drones and fighter aircraft.

At least 64 Israeli soldiers died in that operation. More than 2,000 Palestinians died, including hundreds of Hamas fighters. The IDF claimed it destroyed dozens of tunnels within 4.5 kilometers of the border. But it’s unlikely Israel secured all of them within the limited window of time its troops had to find and clear the underground passageways. Recently, Hamas took reporters on a tour of one tunnel that Israel missed (see Jeffrey Heller and Giles Elgood, “Exclusive: Hamas fighters show defiance in Gaza tunnel tour“, Reuters, 19.08.2014).

As Israeli troops and interior police cracked down on Palestinians in the West Bank — with a focus on Hamas militants based there — other militants retaliated with rocket fire from Gaza. This led Israeli to launch air strikes. Hamas retaliated through tunnel-borne commando raids. It was only then Israel launched its ground invasion. The objective of destroying the tunnels was rationalized after the fact.

Israeli troops during an exercise in August 2014.

Much reporting has focused on the heavy civilian toll in the invasion. This is partly because Israel wants to avoid casualties among its own troops. The IDF prefers to rely heavily on artillery and air strikes to hit its enemies while minimizing danger to itself. There’s also Israel’s reliance on overwhelming force as a means of deterrence, owing to Israel’s small size and vulnerability to stand-off weapons such as rockets and missiles. In short, Israel emphasizes striking hard and striking fast.

But Israel also cannot sustain a long war. As casualties mounted — three times that of Operation Cast Lead more than four years ago — the Israeli government felt the pressure to withdraw sooner rather than later. This means the IDF overcommitted to a plan that had no clear way to succeed. Effectively destroying the tunnels and deterring Hamas meant a price Israel wouldn’t likely be willing to pay.

For an undeterred Hamas, it will continue rocket fire as a means to pressure Israel into lifting its siege on Gaza, which has led to the collapse of numerous industries and makes the Strip nearly unlivable. Since the resumption of fighting (initiated by Hamas), the militant group has fired several hundred mortar rounds and rockets into Israel. One Israeli citizen in Eshkol was badly wounded in one such attack. But 29 Palestinians died on Aug. 21 alone in Israeli air strikes.

The chances for a ceasefire rests with Egypt. “The end of the operation, we believe,” an Israeli official told Haaretz, “must go through Cairo.” But the Egyptian regime under Abdel Fattah al-Sisi is hardly sympathetic to Hamas. The result is deadlock and a push-button war that won’t likely see Israeli ground troops committed again for perhaps years.

That’s a strategy for Israel, on paper. But it’s not a means to end the conflict.